Devo don't actually strike me as THAT add for sporting events...
Good old Enix. I remember when they were their own company too. Remember Irem, Jaleco, Interplay? I've got the FF6 booklet, I kept my instruction booklets in a big pile next to my system.
That FF1 dungeon thing sounds similar to the moon in FF4 where you encounter "behemoth" enemies constantly. FF5 also had the battles towards the end with Shinryuu and Omega Weapon, which were similar to the optional Ruby/Emerald Weapon battles in FF7.